Computer temperature accuracy

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skynscuba

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• Jan 8, 2003

• #1

What accuracy do you get for the temperature reading on your computer? I was checking out my new gear in my pool, and the computer read suspiciously cold. Further checks showed that it is low by ~2F at 70F, but low by about 7F at 40F. I can do that well without a temperature gauge! This is for a new DataMax Pro Plus. Oceanic says they only check them at 71F, where they spec +/-3F.

skyNscuba

 

stiebs

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• Jan 9, 2003

• #2

I don't hold a lot of faith in the temperature guage on my Suunto Stinger. On my wrist above water, it usually shows around 37C (98F).

On my last dive, attached on my wrist over a 7mm wetsuit, it showed:
20C (68F) air temp - about right.
18C (64F) surface temp - about right.
18C (64F) at 100fsw - about wrong.

 

nickjb

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• Jan 9, 2003

• #3

I've always been a bit sceptical. I often feel warmer or colder than the guage suggests. That said, I have three temperature guages built in to various bits of kit and they always are within 1 deg C of each other. I have an accurate temperature probe and I was going to test them in a bowl of water one day. Maybe I'll actually go and do it.

 

MonkSeal

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• Jan 9, 2003

• #4

froop once bubbled...
I don't hold a lot of faith in the temperature guage on my Suunto Stinger. On my wrist above water, it usually shows around 37C (98F).

Click to expand...

about right

On my last dive, attached on my wrist over a 7mm wetsuit, it showed:
20C (68F) air temp - about right.
18C (64F) surface temp - about right.
18C (64F) at 100fsw - about wrong.

Click to expand...

Does Suunto use the temperature as one of the variables in RGBM algorithm ?

If it does (as I believe) then termometer has to be accurate.

 

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yknot

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• Jan 9, 2003

• #5

It's not just absolute accuracy of dive computer temp gauges that affects outcome but how quickly they repond. A tech at Suunto told me the sampling rate for my Vyper was every second. I would believe this for depth but don't think that temp can react that quickly. Temp would have to be electronic and possibly in the time it would take to react you are already somewhere else. I say this because my experiences with mine have all involved thermoclines. It looks like the current display doesn't change nearly as fast as what I feel. Also, if I replay a dive from the memory the max. low temp during the dive is a bit different than what I recall seeing displayed during the dive.

 

stiebs

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• Jan 9, 2003

• #6

MonkSeal once bubbled...

Does Suunto use the temperature as one of the variables in RGBM algorithm ?

If it does (as I believe) then termometer has to be accurate.

Click to expand...

You have me thinking. I realise that it shows the correct temperature while on my wrist, and the air temp when over my wetsuit is good too.

As far as temperature at depth, I haven't actually looked while down there, but only really took notice when I downloaded it to the PC. Maybe there is something wrong with the stored data, not the measured data. I will take notice on my next dive.

BTW, if the watch shows body temperature while I'm wearing it on the surface, will the temperature be skewed when diving with no wetsuit in warm water?

 

MonkSeal

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• Jan 10, 2003

• #7

froop once bubbled...
BTW, if the watch shows body temperature while I'm wearing it on the surface, will the temperature be skewed when diving with no wetsuit in warm water?

Click to expand...

Probably not too much because influence of the water to the sensors is bigger then the one that your body makes. Water cools your body (20 times more than air) especially your skin which is your computer closest to. Also Stinger has few sensors so it probably calculates some kind of average temperature.

BTW Teperature of warm water is closer to your body temperature.

 

madmole

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• Jan 10, 2003

• #8

No Suunto web site, manuals or software make any mention of the deco algorythm using the temperature, its for display only

Only Uwatec are stupid enough to do that. The DUMB range penalise the diver for diving in cold water even when he's sweating his nads off in a drysuit